海洋环境变化对北太平洋柔鱼耳石形态的影响

Effects of marine environment variation on the statolith morphology of neon flying squid (Ommastrephes bartramii) in the north Pacific Ocean

根据2012年(PDO冷期拉尼娜年)、2015年(PDO暖期厄尔尼诺年)和2016年(PDO暖期拉尼娜年)7—10月我国鱿钓船在北太平洋海域采集的柔鱼样本,分析年际间不同性别个体的耳石形态特征差异,并探究耳石形态对海洋环境变化的响应。结果发现,北太平洋柔鱼不同年份和不同性别的耳石形态特征存在显著的差异,PDO冷期厄尔尼诺年(2012年)和PDO暖期厄尔尼诺年(2016年)形态值均大于PDO暖期拉尼娜年(2015年)形态值。主成分分析结果表明,耳石总长(TSL)、翼区长(WL)、吻侧区长(RLL)可以表征耳石长度特征,最大宽度(MW)、翼区宽(WW)、吻区宽(RW)可以表征耳石宽度特征。通过方差分析发现TSL、WL、RLL、MW与胴长之间存在显著的相关性,且不同海洋环境年份和不同性别均存在显著差异,而WW、RW与胴长之间没有显著的相关性。结合各月索饵场的海表面温度(sea surface temperature, SST)和叶绿素a(chlorophyll-a,Chl.a)质量浓度分析发现,在适宜范围内,较高的SST和Chl.a质量浓度对应较大的耳石。

According to the 356 Ommastrephes bartramii samples collected by Chinese jigging fleets in the north Pacific Ocean from July to October in 2012(La Ni1 a year in PDO cold phase),2015(El Ni1 o year in PDO warm phase) and 2016(La Ni1 a year in PDO warm phase). The statolith morphometrics by year and sex were analyzed, combined with the marine environment variation influence on the morphological variation of statolith. The results showed that significant differences of morphological variation of statolith were found by year and sex. The values of morphologic parameters of statolith in both cold(2012) and warm(2016) PDO phase of La Ni1 a year were greater than those in El Ni1 o year(2015). The result of principal component analysis indicated that total statolith length(TSL), wing length(WL), rostrum lateral dome length(RLL), maximum width(MW), wing width(WW) and rostrum width(RW) could be used as the characteristic parameters of statolith. The analysis of variance(ANOVA) showed that significant correlation was found between TSL, WL, RLL and MW versus mantle length(ML), while no significant correlation was found between WW and RW versus ML by year and sex. According to the SST and Chl.a mass concentration on the fishing ground, higher SST and Chl.a mass concentration in suitable range corresponded larger size of statolith.